As the trend towards smaller acoustic devices, e.g., telecommunication products, continues, engineers are experiencing increased challenges in designing these smaller and smaller devices while maintaining acceptable acoustic performance. An example is the well known “flip phone” which can be used as a conventional cellular phone or in a high audio mode that includes both speaker phone operations as well as walkie-talkie modes (also known as dispatch modes). When operating in a high audio mode, the flip part of the phone is able to be closed and then physically blocks the microphone mounted in the base of the phone. It is desirable for such a flip phone to have the same microphone acoustic performance regardless of the position of the flip part of the phone. Stated differently, the high audio operation of such a flip phone should not appreciably vary when the flip part is open or closed. Some conventional designs provide an acoustic pathway in the form of a large gap or a groove between the flip part and the base of the phone that acts as an acoustic channel for the audio signal. An acoustic pathway can also be provided between the two parts of the closed flip phone by placing bumpers in the area between the two flip phone parts so that an air gap is provided when the flip phone is closed. Providing these gaps or groves enhances acoustic performance by preventing blockage of the microphone when the flip is closed. These gaps provided by bumpers, however, add thickness to the phone when it is in the closed position, which limits a designer's ability to produce the ever smaller, and especially thinner, acoustic devices such as flip cellular phones that are in demand. The use of bumpers can also increase the number of parts in the phone assembly. Furthermore, these bumpers and groves can cosmetically detract from the phone.
Therefore a need exists to overcome the problems with the prior art as discussed above.